Sunlight crosses about 1/(sin h) times as much air as from overhead.
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Sunlight crosses about times as much air as from overhead. How many times more air does light cross when the Sun is high than when it is high? Use your answer to explain the colours of the Sun.
Need a reminder? The key ideaShow
The sky is blue because air scatters blue toward us from every direction. Near the horizon sunlight crosses much more air, about times as much for a Sun degrees high, so most of the blue is scattered away and the Sun looks red.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. At . times the overhead air.
Step 2. At . times.
Step 3. The ratio. .
Answer: about times as much air. Crossing so much air, the low Sun's light loses most of its blue and looks red; the high Sun's light loses little and looks white.
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